The Post-buckling Behaviour of Laterally Restrained Columns

The elastic plastic post-buckling behaviour of a column, laterally restrained near one flange and subjected to a uniform major axis bending moment, is investigated, using the concept of a complex plastic hinge situated at mid-height. By considering also the elastic response curve in the presence of initial imperfections, an upper bound to the complete elastic-plastic load deformation relationship is derived. It is shown how this analysis may be used to derive suitable slenderness ratio limits in plastic design
procedures for frames containing such members.

M.R. Horne and J.L. Ajmani